Brake Pedal angles RV-6 & 7 models

[Graham]

Folks

I have just bled my brakes for the first time on my 15 year old project to slow build my RV6. Prior to this I had set the BRAKE pedals to "vertical" but found that this deos not feel right. I believe that the brake pedals need to be fwd of the vertical by a suitable amount. I tried them at 5 degrees but even that didn't seem enough. Of course what I am aiming for is not accidentally using the brake pedals when applying rudder.

I have done full scale sketches showing my interpretation of the geometry. They also show some simple angle scraps which I am using to set up the required angle. But I cant figure how to attach these sketches to this inquiry.

The setting of pedal angle appears to be a process of trial and error.

Anyway my question is has anybody done any similar geometry exercises, and especially has anybody with a good setup measured the brake pedal angle relative to the same rudder pedal angle with brakes off?"

Due to rudder pedal geometry this angle is different for the LH & RH pedals.

I would be very grateful for any input including telling me that I am being too darned fussy.

Thanks team,

Graham
Blenheim
New Zealand

[PCHunt]

G'day Graham,

This gives me a chance to tout my friend Robby Grove's brake master cylinders!

Grove Aircraft offer master cylinders that have an adjustable ram, which allows easy selecting any pedal angle you prefer. I have a set and love them!

All the best........

[WingsOnWheels]

I am tall with long legs, so the pedals are of particular concern to me. I'm not done building yet, but what I did to improve the geometry is to shift the pedal assembly forward but keep the cables a little short so that the rudder pedals are not vertical with neutral rudder. So the pedal bottoms are closer than the top adding angle to the whole assembly, then less difference is required between the brake and rudder pedal angle. Plus it is easy to remake the little splice plates between the cable and pedal.

[Raymo]

I have mine set like Colin described but still building too.

[az_gila]

The other option is to move the pedal cross bar towards the pilot with a clamp on extension and leave the brake portion alone.

http://www.jdair.com/rudder-pedal-ex...-7-rv-9-rv-10/

http://www.mlblueskunk.com/Rudder_pedal_Extensions.html

...or a DIY equivalent...

[Pittsartist]

I struggled quite a bit in doing this.

In the end I assembled everything, then clamped 2 long lengths of alloy angle as below

1) Across the tips of all the brake pedals to get them all in line relative to each other regardless of rudder bar positions.
2) To the lowest part of the rudder bars (the bit your foot actually sits on)

Finding a reference point is difficult since the rudder bars are not hanging down vertically.

In the end I set the rudder bars so that the alloy clamping angle was at the mid point directly underneath the 2 top tubes (ie exactly vertical below the centre point of the plastic mounting blocks).

Then I set the tips of the rudder pedals to be 30mm forward of the point described above. In practice this put the clamping angle just behind the line of the forwardmost rudder bar.

After I'd flown the aircraft for 20 hours I then decided to make some of the pedal extensions described (and sold by JD Air) as I was still struggling slightly to keep of the brakes when taxiing

It seems to me that it is important to consider the angle of the pedals AND the distance that the rudder bars are set at when doing this. If I did it all again I would drill 3 sets of mounting holes for the rudder bars at 1" spacings to allow for adjustment and then make 3 sets of corresponding rudder cable link plates to go with the above.

Here's a picture - (this what the pedals look like when they are too upright and need to be angled forward more)

[IMG]IMG_3339 by WIGY TV, on Flickr[/IMG]

[rvsxer]

I had exactly the same problem with my -6. I made a few more sets of those "pork-chop" shaped horns that rivet to the side of the rudder pedals and connect to the master cylinders. If you lengthen the leg a little you can move the tips of the pedals forward a bit. I built the whole thing on the bench so I could experiment. First, establish the basic rudder-bar angle (I made mine slightly aft of vertical). Then clamp both pedals at the same angle and mark for the hole for the master cylinder bolt. The left and right horns will be slightly different to achieve the same pedal angle. Worked great.

[PaulR]

One of the after market companies used to have some fancy AL extrusions that fit over the rudder bar and made it quite a bit larger to help eliminate the problem with hitting the brakes. Anyone know who might have them?

[Doug]

I had no problem making the standard parts work.

As others have said assemble the break/rudder pedal weldments into the hinge blocks and clamp the 3/4" angle and brake pedal in place, I used small angle clamps. Then organise the pedals to be in the same plane in the neutral position (ie when the bottom pedal bars are aligned). The 3/4" angles were just clecod to the pedals iirc.

I was concerned too that when the actual position was finally adjusted (by setting the joiner lengths) it would throw the brake pedal angles out - but if it did it was so little it did not matter one bit.

Easier to do than describe.

[rightrudder]

Originally Posted by rvsxer

I had exactly the same problem with my -6. I made a few more sets of those "pork-chop" shaped horns that rivet to the side of the rudder pedals and connect to the master cylinders. If you lengthen the leg a little you can move the tips of the pedals forward a bit. I built the whole thing on the bench so I could experiment. First, establish the basic rudder-bar angle (I made mine slightly aft of vertical). Then clamp both pedals at the same angle and mark for the hole for the master cylinder bolt. The left and right horns will be slightly different to achieve the same pedal angle. Worked great.

I used the stock "pork chops" but drilled the attach hole for the master cylinder a little lower down. So with the rudder pedals hanging straight down, the brake pedals angle forward enough to prevent brake actuation when only rudder input is desired.